The present invention relates to an automatic lubricating device for a remotely operable bowden cable.
For example in remotely operable brake mechanisms or clutch mechanisms in various vehicles, use is made of a bowden cable (sometimes called a release cable or push-pull cable) consisting of an outer wire in the form of a coiled spring covered with a plastic tube and an inner wire in the form of a stranded wire inserted in said outer wire, said bowden cable being operatively connected between the actuating means and operating means for said mechanism so that when the inner wire is pulled to operate said mechanism, a relative movement is produced between said inner and outer wires. In this connection, problems arise in that a frictional phenomenon is produced in the relative slide interface between the two wires, thus interfering with the smoothness of the remote operation and decreasing the durability of the bowden cable.
To solve the problems, there has heretofore been placed on the market a bowden cable having lubricating oil applied to the relative slide interface between the two wires in advance.
However, when such bowden cable is put to long-term use and the inner wire is repeatedly operated by being pulled, the lubricating oil will soon dry up, resulting in the loss of the lubricating performance of the relative friction slide interface. Practically, it is very difficult to re-inject lubricating oil into the bowden cable once installed between the actuating means and operating means of said mechanism. In other words, in order to replenish the relative friction slide interface with lubricating oil, the opposite ends of the bowden cable must be completely separated from the actuating means and operating means of said mechanism and the inner wire must then be withdrawn from the outer wire, such operation requiring much trouble. Moreover, after the application of lubricating oil, the opposite ends of the bowden cable must be installed in said mechanism. Since such is the present situation, even if the lubricating performance of the bowden is aggravated, the tendency is to continue using it without replenishment of lubricating oil.